september 2018

4-8 weeks – from pregnancy hormones and symptoms to baby’s early developments

pregnancy Recommended Products
4-8 weeks pregnancy hormones and symptoms to baby’s early developments

4-8 weeks pregnant

Welcome to the second instalment of our week-by-week pregnancy guide. Here we explore what happens in the early days of the first trimester of pregnancy during weeks 4-8:

Week 4

Although there are no outward, physical signs yet that you are pregnant, many changes are taking place within your body during this time. Your hormones are changing as your body starts to nurture and support your baby by providing an optimal environment for the next nine months. These hormonal changes can cause heightened emotions, tiredness and sickness.

You probably won’t suspect that you are pregnant until you miss your usual period at 4-6 weeks. A pregnancy test can be taken at this point, as they are quite sensitive and can usually detect your pregnancy hormones.

Your baby is now at the embryonic stage of development, and being nurtured in the blood-rich lining of your womb. In the first trimester of pregnancy, your baby will undergo amazing changes and developments. From an initial ball of cells, three separate layers of cells will develop to form your baby:

  • The internal layer (endoderm)

This develops into your baby’s digestive system, lungs and bladder.

  • The middle layer (mesoderm)

This develops first to form the heart, blood and circulatory system to sustain the development of your baby’s organ systems. This system also nurtures your baby with essential nutrients and carries away waste products via the placenta, which has yet to develop. 

  • The external layer (ectoderm)

This part forms your baby’s nervous system, brain, teeth, skin and nails, as well as developing into the placenta too.


Week 5

Your baby is still being nurtured in a small yolk sac, whilst your placenta is in the process of forming. Small blood vessels are developing which will connect you and your baby and form into the umbilical cord.


Week 6

Your baby resembles a tadpole shape, with a large head and curved body. The beginnings of your baby’s arms and legs are forming, and your baby’s heart can be seen visibly beating on some types of ultrasound scans.


Week 7

Your baby is still tiny, measuring just 10mm, however, the nervous system and brain are growing quickly and the eyes and ears are developing.


Week 8

Baby is now developing fingers and toes. If you haven’t yet contacted your GP or midwife, you may now want to confirm your pregnancy and book in to the maternity care system.


Coping with early pregnancy related symptoms:

Sickness and nausea

This can range from feeling slightly nauseous at various times of the day or night, to it being quite debilitating due to feeling sick constantly. Intermittent sickness is quite normal, so listen to your body and rest and relax where possible.

Eat and drink regularly; try small amounts often rather than big meals. Eating plain foods can help, such as toast, biscuits and pasta. Drinking peppermint tea or eating ginger-infused foods can ease pregnancy nausea and ‘morning sickness’. Our previous blog can help with other food and drink to eat and avoid when pregnant. 

If you can’t keep food and fluids down for days, you may become ill from dehydration so consult your GP or midwife. In extreme conditions, this is known as hyperemesis gravidarum, which can mean a stay in hospital or medication to help alleviate the sickness. For most women the sickness will start to subside by week 14 of pregnancy.


Increased need to pass urine

Your kidneys start to produce more urine due to an increase in blood flow to the pelvic area. This usually peaks during the first trimester and then settles after 12 weeks of pregnancy. Although the uterus is still small, (about the size of a large orange), it is very close to your bladder and can press against it from early on in your pregnancy.


A heightened sense of taste and smell

You may find that you actively avoid certain foods and smells, which can include tea, coffee, tobacco or certain meats.


Tender breasts

Your breasts are undergoing lots of changes, driven by pregnancy hormones, as they start to prepare to produce milk to feed your baby. They may become very sensitive to the slightest touch, so wear a well-fitting bra to help with support.


Bloated tummy

Your tummy may start to feel a little bloated due to hormonal changes. An increase in the hormone progesterone can relax tummy muscles and your digestive system, causing this gassy, bloated feeling. Gently massaging the abdomen can help to relax this swollen feeling.



It can be very worrying if you see any spotting (red or brown vaginal discharge). This can be a sign of miscarriage if it continues or is accompanied by tummy cramps. However, it can also be a symptom of normal pregnancy as your baby embeds into the lining of your uterus. Contact your midwife or GP if bleeding becomes heavy.


If your pregnancy test is positive during these early weeks it is highly unlikely to be wrong, as it will be detecting the presence of certain hormones specific to being pregnant. A negative pregnancy test early on may not be as accurate, as your hormone levels may not quite be high enough for detection. Test again in another week or so.


What’s next

Pop back to see the next instalment of the week-by-week series; 8-12 weeks of pregnancy.

If you missed what happens from 0-4 weeks, take a look at our previous blog on going from your last period to getting pregnant.